Let's break this down. We're going to add 7215 and 2302 together.

Step 1: We'll start by adding the digits 5 & 2 in column 1 and get 7.

Step 2: We'll start by adding the digits 1 & 0 in column 2 and get 1.

Step 3: We'll start by adding the digits 2 & 3 in column 3 and get 5.

Step 4: We'll start by adding the digits 7 & 2 in column 4 and get 9.

So, 7215 + 2302 = 9517.

